
<!DOCTYPE html>
<html>

<head>
    <meta charset="UTF-8" />
    <link rel="stylesheet" href="./cesium/Cesium1.98/Widgets/widgets.css">
    <script type="text/javascript" src="./cesium/Cesium1.98/Cesium.js"></script>
</head>

<body style="margin: 0; overflow: hidden; background: #fff; width: 100%; height: 100%; position: absolute; top: 0">
    <div id="map" style="margin: 0 auto; width: 100%; height: 100%"></div>
    <script type="text/javascript">

        Cesium.Ion.defaultAccessToken = 'eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJqdGkiOiI3ZjQ5ZGUzNC1jNWYwLTQ1ZTMtYmNjYS05YTY4ZTVmN2I2MDkiLCJpZCI6MTE3MTM4LCJpYXQiOjE2NzY0NDUyODB9.ZaNSBIfc1sGLhQd_xqhiSsc0yr8oS0wt1hAo9gbke6M'
        const viewer = new Cesium.Viewer('map', {});

        // 开启帧率
        viewer.scene.debugShowFramesPerSecond = true;

        // 清除默认地形
        viewer.scene.terrainProvider = new Cesium.EllipsoidTerrainProvider({});

        // 加载火星地形
        viewer.terrainProvider = new Cesium.CesiumTerrainProvider({
            url: 'http://data.mars3d.cn/terrain'
        });

        // 加载本地地形
        // viewer.terrainProvider = new Cesium.CesiumTerrainProvider({
        //     url: 'http://localhost/tdt/dem_30m'
        // });

        // 监听地形提供者的ready事件
        viewer.terrainProvider.readyPromise.then(function (terrainProvider) {
            // 地形已加载完成，可以进行相关操作
            console.log('Terrain is now ready.');
        }).otherwise(function (error) {
            // 地形加载失败，处理错误
            console.error('Terrain error: ' + error);
        });

    </script>
</body>

</html>